30 — M
achinist
c
alc™
/ M
achinist
c
alc™
P
ro
RPM -
Drilling
Calculate what the RPM (Spindle Speed) should be set to
when drilling into material with a recommended Cutting Speed
of 90 sfm using a 5/8” bit:
KeYSTROKe
DISPLAY
O O
0.
1. Enter the Diameter:
5 / 8 d
DIA
0-5/8
INCH
2. Enter the Cutting Speed:
9 0 C
CUT
90.
feeT/MIN
3. Calculate the RPM:
R
*
RPM 550.
* Repeated presses of
R
will toggle through the inputs and outputs,
starting with the entered Cutting Speed.
FEED PEr TOOTH (cHIP lOaD)
Feed per Tooth, or Chip Load, is the thickness of material
removed by each cutting surface. You can calculate Feed per
Tooth given values for Number of Teeth and Cutting Feed.
If the Cutting Feed is not known, the Feed per Tooth can be
calculated given values for Number of Teeth, Feed Rate and
RPM (Spindle Speed).
feed per Tooth –
Based on Cutting Feed and # of Teeth
Calculate Feed per Tooth (Chip Load) with a Cutting Feed of
0.024 Inches for 4 Teeth:
KeYSTROKe
DISPLAY
O O
0.
1. Enter the Cutting Feed:
. 0 2 4 c
CUT
0.024
INCH/ReV
